I've not sold art nor done commissions for actual cash, but I have done a couple of point commissions. I charge 100-1000 points for digital, and if I decide to do traditional commissions I've set my prices to 100-2000 points.
Hm, payment depends on the job. Usually do jobs for around $30-$60 and I don't do super involved art, that's for simple color or lineart. I don't generally take commissions for nice super pretty digital paintings but the lowest I could go on one of those would probably be more around $150 unless I just really liked the subject and wanted to see it done.
Not that I don't kick out a $5-$10 job once in a while. I'm more likely to take those as point commissions so I can do a paid membership here.
I haven't tried to sell any of my sculpture and stuff, I don't even know what I'd start pricing that at. Maybe lowest would be $25, but again, talking more in the $150 and up range just because of time involved, and I'm rather attached to them so it really needs to be worth it for me to part with them.
Then glass (which I don't currently have any pictures posted of) for that the general price range right now would be $10-35 because I'm just getting started again and not doing anything big or involved. That's prices for paperweights and up to drinking glasses and ornaments (that I'm not making again yet).
When I was doing fused glass (sold all that, so no pictures) average price was about $35 for little ornaments and $150-250 for bigger or more involved pieces.